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RISKS-LIST: RISKS-FORUM Digest Thursday, 7 January 1988 Volume 6 : Issue 5

FORUM ON RISKS TO THE PUBLIC IN COMPUTERS AND RELATED SYSTEMS ACM Committee on Computers and Public Policy, Peter G. Neumann, moderator

Contents: Re: PCs die of New Year Cerebration (John Owens, Paul F Cudney) Source code vs. attacks -- Avoidance techniques (David Collier-Brown) Ham Radiation and Cancer (Barry Ornitz [long], Martin Ewing, Douglas Jones)

The RISKS Forum is moderated. Contributions should be relevant, sound, in good taste, objective, coherent, concise, nonrepetitious. Diversity is welcome. Contributions to RISKS@CSL.SRI.COM, Requests to RISKS-Request@CSL.SRI.COM. > > > > > > > > > PLEASE LIST SUBJECT in SUBJECT: LINE. < < < < < < < < < For Vol i issue j, FTP SRI.COM, CD STRIPE:<RISKS>, GET RISKS-i.j. Volume summaries in (i, max j) = (1,46),(2,57),(3,92),(4,97),(5,85).

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Date: Thu, 07 Jan 88 12:43:11 EST From: John Owens <OWENSJ@VTVM1.CC.VT.EDU> Subject: Re: PCs die of New Year Cerebration

Scot E. Wilcoxon writes:

>One of my clients has just reported to me that a certain brand of >PC-compatibles which they sold in 1984 suddenly stopped working when 1988 >was reached...

Just to avoid any confusion, it is quite unlikely that Scot is referring to a PC-compatible at all, but to a problem with Sun Microsystems UNIX workstations. Recent versions of the operating system had a bug in the time of day code which caused a warning message at boot time and problems setting the time _in a leap year_.

(The bug was caused by an expression with a side effect being passed as an argument to a macro which evaluated the expression twice.)

Sun has published the fix on various mailing lists and USENET groups; if you have the problem and don't have the patch, send mail to chuq@sun.com.

-John Owen, Virginia Tech Communications Network Service OWENSJ@VTVM1.BITNET +1 703 961 7827

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Date: Thu, 7 Jan 88 00:02 EST From: Paul F Cudney <Cudney@DOCKMASTER.ARPA> Subject: Leaping Clocks

... Although resolved in just a few days, [this problem] highlights our assumption that workstation "owners" are OS-wise (or can obtain competent assistance). With the ubiquitous spread of ever more complex systems, shouldn't we be demanding self-validating system maintenance tools useable by un-OSphisticated users? Paul

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From: geac!daveb@uunet.UU.NET (David Collier-Brown) Subject: Source code vs. attacks -- Avoidance techniques Date: 6 Jan 88 18:50:12 GMT Organization: Geac Computers Corporation Ltd.

Chris Torek <chris@mimsy.umd.edu>, comments: What, then, are we to do? Form a software users' union? (I am only half joking.) I would very much appreciate receiving source code to the binaries I must run..

In fact, the Honeywell Large Systems User's Group is such a union, and votes semi-annually on features to be required or to be removed from Honeywell (now -Bull) software. One of the fallbacks from requiring improved maintenance, is to require source code. This also is the normal behavior when HW when a system is to be taken off maintenance (ie, one normally gets either maintenance or source, but not both).

David Collier-Brown, Geac Computers International Inc., 350 Steelcase Road, Markham, Ontario, CANADA, L3R 1B3 (416) 475-0525 x3279 {mnetor|yetti|utgpu}!geac!daveb

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Date: Wed, 6 Jan 88 23:07:43 EST From: ucbcad!ames.UUCP!rochester!kodak!ornitz@ucbvax.Berkeley.EDU (barry ornitz) Subject: Ham Radiation and Cancer

[The following is an article I posted on the subject of Cancer and Electro- magnetic Radiation. I have received several replies on my posting; two disputed Dr. Milham's statistics based on Poisson distributions, and one mailed an article on Milham's previous article in 1985 in Lancet. Barry]

In yesterday's newspaper, I noticed with great interest an article entitled

"Link suggested between cancer, electromagnetic fields."

The article had the byline of the Associated Press, Tacoma, WA. It was stated in the article that "amateur radio operators in two states appear to die at abnormally high rates from several forms of cancer, suggesting a possible link between cancer and electromagnetic fields, according to data collected by a state epidemiologist." This article appears to be prompted by work published in the American Journal of Epidemiology by Dr. Samuel Milham Jr. of the Washington Department of Social and Health Services. According to the article, Dr. Milham studied the deaths of 2,485 Washington and California amateur (ham) radio operators between 1979 and 1984. Based on a population this size, he found the following data:

Expected Actual Cause Deaths Deaths ------------------------ ----------------------- ----------- Leukemia 29 36 Lymphatic & Blood Forming Organ Cancers 72 89 Prostate Cancer 67.6 (!) 78

I am not sure about the statistical differences between these numbers, but I am certain that a trained epidemiologist would check the statistical significance of his data before publishing. Dr. Milham is further reported to have concluded that "amateur radio operator licensees in Washington state and California have significant excess mortality due to acute myloid leukemia, multiple myeloma and perhaps certain types of malignant lymphoma."

The Associated Press article also quoted Leonard Sagan, program manager for radiation studies at the Electric Power Research Institute in Palo Alto, CA. Sagan warned that studies like Dr. Milham's could be misinterpreted, and that the "findings could be simple associations that have nothing to do with cancer causes among people who work with electricity."

Having been an amateur radio operator for over twenty-three years, and having been concerned with the safety of exposure to non-ionizing, radio frequency electromagnetic energy as a small portion of my job, I have a few comments about this article. Before I begin, I should state that my title of Dr. is not a medical one, but rather a PhD in Engineering. I should also state that I have not yet read the article in the American Journal of Epidemiology.

The medical effects of exposure to electromagnetic radiation have been shown to be frequency dependent. This is logical since as the wavelength of radiation approaches the dimensions of the human body, absorption of the radiation is enhanced due to more efficient coupling into the body. At higher frequencies (shorter wavelengths), typically in the microwave region, the electromagnetic radiation is absorbed near the surface of the body. The ANSI standards for exposure to radio frequency energy take this information into account, placing the most strict requirements on frequencies in the VHF (very high frequency) region. Amateur use of the VHF spectrum, while dating back over fifty years, has primarily been negligible until twenty years ago. Amateur transmitter power levels in the VHF region have generally been much lower than the power levels used in the high frequency bands. Antenna placement for VHF, in terms of wavelengths from the amateur's operating position, is generally high. These three facts would tend to cancel the increased hazard of VHF radiation. To test Milham's hypothesis further, a study of FM broadcast engineers, commercial two-way radio technicians, and television transmitter engineers should be performed since these persons are all exposed to various levels of VHF radiation. The highest field strengths to which amateur radio operators are normally exposed come from the near field antenna radiation during high frequency operation. Power levels of up to two kilowatts may be used with antenna placement often below a wavelength. It should be noted that exposure to this power level is intermittent in most amateur operation. If Milham's hypothesis is correct, broadcast technicians and engineers for commercial AM and especially short wave broadcast stations, as well as military communication operators should show even higher levels of cancer deaths than hams. Operation on microwave frequencies by amateur radio operators is rare; furthermore, I would expect any cancers caused by microwaves to be other than deep tissue cancers. A study of the eyes for cataracts would be in order, too, since microwave exposure generally causes eye problems prior to additional damage in the human body.

I believe that other causality should be investigated by the medical profession before Dr. Milham's conclusions are accepted. I would expect that the amateurs studied by Dr. Milham were mostly individuals who had been hams for many years. An analysis including the length of time that the amateurs were licensed (or at least active) would be in order. I believe that this analysis would show some increased mortality (adjusted for age, of course) for the older hams. If this increased mortality exists, I feel that other environmental factors should be studied in addition to exposure to electromagnetic fields.

Until twenty-five to thirty years ago, much of the amateur radio equipment in use was home constructed. The construction of electronic equipment at this and especially prior years, exposed the amateur to a number of chemical hazards, many of which were not known as hazards at the time. For example, I would expect to see higher than normal levels of metals in older hams such as tin, lead, bismuth, antimony, and cadmium (from soldering); mercury (from broken rectifier tubes and relays); barium, beryllium, and rare earth oxides (from broken vacuum tubes and phosphors from cathode ray tubes); radium (from luminescent dials); selenium (from rectifiers); and manganese and zinc (from batteries). Likewise these hams would have been exposed to rosin fumes containing numerous organic acids (from soldering), paint solvents and cleaning fluids such as benzene and carbon tetrachloride, phenol (from burnt phenolic insulators), and asbestos. Even more insidious, however, was the exposure to transformer and capacitor impregnating oils. These oils often contained poly-chlorinated biphenyls (PCB's) as flame retardants, sometimes in quite high concentrations.

These chemical hazards were not unique to amateur radio operators only. Other electronic hobbyists as well as people manufacturing electronic equipment would have been exposed to similar hazards. I feel that it would be prudent to compare mortality rates of workers in oil-filled capacitor manufacturing plants to those of the hams studied [for example, the Sangamo capacitor plant in Pickens, SC, which until several years ago was a major user of PCB oils].

In conclusion, I believe that other causal relationships between cancer deaths and amateur radio operators may more adequately explain Milham's data. I propose that Milham or other epidemiologists expand their study to include the other occupations I have suggested above. I further propose that age-adjusted mortality rates be calculated for the existing data to determine whether length of exposure or date of exposure is significant and whether chemical exposure of these hams might be significant. I am certain that electromagnetic radiation has effects on the human body, but I do believe that electromagnetic radiation is not the major cause of the increase in cancer deaths as stated by Dr.Milham.

For those persons interested in further study on the effects of electromagnetic radiation, I would suggest the American National Standards Institute document ANSI C95.1-1982, Safety Levels with Respect to Human Exposure to Radio Frequency Electromagnetic Fields, 300 kHz to 100 GHz. This standard contains an appendix listing numerous references on the biological effects of radio-frequency electromagnetic fields. A number of other standards exist for radio-frequency and microwave exposure; many of these are listed in the Microwave Engineer's Handbook, Vol. 2.

If anyone has read Dr. Milham's original article, I would appreciate their sending me the exact title and the date of publication so I might have our library order a copy. I would also appreciate the comments of other amateurs as well as physicians on this subject. Please email responses directly to me and I will summarize or cross-post your replies to both rec.ham-radio and sci.med (many hams on ARPA receive their postings via an automatic mailing list rather than a newsgroup).

Thanks and 73 [ham radio jargon for best regards]. Barry L. Ornitz WA4VZQ

Dr. Barry L. Ornitz UUCP:...!rochester!kodak!ornitz Eastman Kodak Company, Eastman Chemicals Division Research Laboratories P. O. Box 1972, Kingsport, TN 37662 615/229-4904

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Date: Wed, 6 Jan 88 17:37:01 PST From: msesys@DEImos.Caltech.Edu (Martin Ewing) Subject: Risks of Amateur Radio

I also noted Dr Milham's study of ham radio operators vs cancer statistics. The press report was undoutably mangled, but as a sometime radio amateur, I can add some questions and comments.

Was there any analysis of the actual RF exposure to the amateurs? Typical amateur radio operations involves <<50% of time spent in actual transmission. Typical frequencies range from 3.5 to 220 MHz, and power levels from 5 W to 1 kW. Emission modes vary, but single-sideband voice is most common up to 30 MHz; SSB duty cycles are <<100% even when transmitting. Antennas range from large yagi arrays on high towers to loaded 1/4 wave "rubber duckies" held next to the head while using VHF handheld equipment. Many licensees are inactive, too.

Was there any demographic control? Ham operators have a peculiar distribution, with "peaks" among young-adult techies and retired middle-class WASP males.

Hams expose themselves to various other potential hazards: solvents and smoke during soldering, PCBs from transformer and capacitor oils, etc. Why should one suspect RF exposure in particular?

Apparently the study came out in a reputable journal, so it may deserve a better review than the AP (and we) are giving it.

Martin Ewing, Caltech

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Date: Wed, 6 Jan 88 11:16:58 CST From: Douglas Jones <jones%cs.uiowa.edu@RELAY.CS.NET> Subject: Re: Ham radios and non-ionizing radiation

Eric Townsend's note raises the possibility of a > link between cancer and electromagnetic fields in the context of a study of cancer cases among ham radio operators.

I would not be surprised to find a link between ham radio operation and cancer for a completely unrelated reason: Ham radio operators tend to work with electronics, exposing them to many interesting chemicals in the process, including lead vapor from hot solder and vaporized solder flux, not to mention coil dope, red glypt, and other oddities. Older ham radio equipment frequently contained large oil-filed capacitors (possibly containing PCB oils), and who can forget the ozone smell caused by the high plate voltages used by pre-1970 transmitters.

I don't mean to imply that there is no risk associated with the high fields around a radio transmitter, after all, you can cook hot-dogs by putting them inside the antenna impedence matching coils, but there are other possible causes of the small increase in cancer risk that was observed.

A good experiment to test these risks would be to look at the cancer rate among model railroaders. They also solder things and work with related chemicals, but the electric fields they are exposed to are produced by a source with a maximum power of 12 watts (12 volts at one amp, DC power to the track). Douglas Jones

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End of RISKS-FORUM Digest ************************